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Outdoor Air Pollution

Am Fam Physician. 2001 Mar 15;63(6):1221-1222.

What is air pollution?

Air pollution is a large number of gases, droplets and particles that reduce the quality of the air. Air can be polluted in the city and the country.

In the city, air pollution may be caused by cars, buses and airplanes, as well as industry and construction. Air pollution in the country may be caused by dust from tractors plowing fields, trucks and cars driving on dirt or gravel roads, rock quarries and smoke from wood and crop fires.

Ground-level ozone is the major part of air pollution in most cities. Ground-level ozone is created when engine and fuel gases already released into the air interact in the presence of sunlight. Ozone levels increase in cities when the air is still and the sun is bright and the temperature is warm. Ground-level ozone should not be confused with the “good” ozone that is miles up in the atmosphere that protects us from radiation.

What symptoms can air pollution cause?

Air pollution can irritate the eyes, throat and lungs. Burning eyes, cough and chest tightness are common with exposure to high levels of air pollutants.

However, responses to air pollution vary greatly in people. Some people may notice chest ightness or cough, while others may not notice any effects. Because exercise requires faster, deeper breathing, it may increase the symptoms. People with heart disease, such as angina, or lung disease, such as asthma or emphysema, may be highly sensitive to exposure to air pollution and may have symptoms when others do not.

Is air pollution bad for my health?

Fortunately for most healthy people, the symptoms of air pollution exposure go away as soon as the air quality improves. However, certain groups of people are more sensitive to the effects of air pollution than others.

Children feel the effects of pollution at lower levels than adults. They also have more illness, such as bronchitis and earaches, in areas of high pollution than in areas with cleaner air.

People with heart or lung disease react more severely to polluted air. During times of heavy pollution, their condition may worsen to the point that they must limit their activities or even seek additional medical care. In the past, a number of deaths have been associated with severely polluted conditions. Today, pollution this bad is rare in the United States.

The health effects of long-term exposure to low levels of air pollution are being studied.

Is there a group that keeps track of air pollution?

The Environmental Protection Agency (EPA) checks and reports on air quality in the United States. Because of their efforts, the nation’s air quality has greatly improved over the past 20 years. The EPA, in cooperation with local air-quality boards, measures the level of pollution in the air over many large cities and a number of rural areas.

Newspapers, television and radio stations often give air-quality reports in areas where pollution is a problem. The Pollution Standards Index (PSI) is a scale of air quality that ranges from 0 to 500 and is used in many weather reports. A PSI score of more than 100 indicates unhealthy air conditions.

What can I do to protect my family and myself?

Check the predicted PSI in your area. Be careful if the PSI is greater than 100. Also, be careful if there are high-risk weather conditions, such as a hot, sunny day, and you begin to have signs like chest tightness, burning eyes or a cough.

You can protect yourself and your family from the effects of air pollution by doing the following:

Stay indoors as much as you can during the day. Many pollutants have lower levels indoors than outdoors.

If you must go outside, limit outside activity to the early morning hours or wait until after sunset. This is important in high ozone conditions (as in many large cities) because sunshine drives up ozone levels.

Don’t exert yourself. The faster you breathe, the more pollution you take into your lungs.

These steps will generally prevent symptoms in healthy adults and children. If you live or work close to a known pollution source, or if you have a chronic heart or lung problem, talk with your doctor about other ways to deal with air pollution.